Measure value method and apparatus

ABSTRACT

A method and apparatus for evaluating electrical measurement values derived from a test stand in which upper and lower tolerance values, stored for example on a punched card, are coverted into analog signals with the upper and lower value signals being applied to one difference forming circuit while the measurement value and one of the tolerance signals is applied to a second difference forming circuit. The resulting difference signals are divided, one into the other, and applied to an analog display.

Heimpreeht [4 Nova 26, 1974 1 MEASURE VALUE METHOD AND 3,534,353 10/1970 Calkin et a1. l. 340/248 A APPARATUS 3,694,635 9/1972 Hoetzel et al 235/1513 3,750,134 7/1973 Wciscnd 340/213 Q X [75] lnventor: Ulrich Stefan Heimprecht,

Darmstadt, Germany Ch 1 E k Primary Exumincr- 4 ar es Atl'inson [73] Assignee: gebel-lofmann KG, Darmstadt, Asst-Mam Examim,r jerry Smith ermmy Attorney, Agent, or FirmCushman, Darby & [22] Filed: Sept. 20, 1973 cushman [21] App]. No.: 399,340

[57] ABSTRACT [30] Foreign Application Priority Data Oct. 16 1972 Germany l 2250717 A method and apparatus for evaluating electrical 4 measurement values derived from a test stand in [52] Ufi Cl 235/15L3 235/15 113 340/213 O which upper and lower tolerance values, stored for ex- 340/248 A 340/411 ample on a punched card, are coverted into analog- 511 int. e1 Gillfig 7/16 Signals with the upper and lower value Signals being [58] Fiend UK Search 5' 184 applied to one difference forming circuit while the 235/196. 324/73 R 73 AT 3 measurement value and one of the tolerance signals is 1 15 R 140 340/l79 213 41 applied to a second difference forming circuit. The resulting difference signals are divided, one into the other, and applied to an analog display. [56] References Cited i UNITED STATES PATENTS 5 Clams l Drawmg 3.151.237 9/1964 Hrabak 235/l5l.l3

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- 3 ,85 1, 160 l 2 MEASURE VALUE METHOD AND APPARATUS first and second difference-forming means being arranged downstream of the digital-analog converter 1 means, a dividing means connected to the outputs of This invention relates to methods and apparatus for the first and econd difference-forming means and a evaluating measuremfim f of a testing Stand. for 5 display means connected to the dividing means for dis? example a motor Vehlcle testmg Standplaying the result of the comparison between the meas- Such a method been P p in which the measurement value and the upper and lower tolerance valurement values obtained on the stand are compared to upper and lower tolerance values which are stored in A b di t f a m thod and apparatus accorda storage medium. Evaluation of the part being tested ing to the present invention will now be described by is then effected in dependence on this comparison, and way of example with reference to the accompanying the result displayed. This method can be carried out by i le FIGURE hi h Shows a i it di f th means of an apparatus, a so-called diagnosis apparatus, apparatus. having a storage means such as a perforated card in Upper and lower tolerance or limit digital values which upper and lower limit or tolerance values in rewhich are stored in the storage means, for example a spect of the parts to be tested are stored, a comparison mmfliedea d, and reatlbya conventional card reader means for comparing the measurement or actual values 1', are converted into analog voltages by two digitalto the respective tolerance values to arrive at a good analog converters 1 and 2. The digitabanalog converter or bad evaluation about the part being tested, and a 1 converts the lower tolerance value into the respective display means for displaying the result of the comparianalog voltage and the digital-analog converter 2 con son. In the case of use with motor vehicles, testing verts the upper tolerance value into the respective anastands and such diagnosis apparatuses can be employed log voltage. The outputs of the two converters l and 2 for example to test settings such as ignition settings or are connected to a first difference-forming means such axle settings. as a differential amplifier 4 in which a difference is A disadvantage of such methods and apparatuses is formed between the analog voltages at the outputs of that it is only possible to make an objective judgment the two converters 1 and 2, which voltages correspond on the condition of the part at that moment, without to the lower and the upper limit value respectively. The any prediction as to the working life or operational effioutput of the converter 1, which corresponds to the ciency still to be expected. For example it is not possilower tolerance value, is also connected to a second ble to directly compare the difference which is already difference-forming means such as a further differential present between the actual value of the measurement amplifier 3. Also connected to the differential amplifier and the ideal value, to the gap between the actual value 3 is a measurement circuit in a testing stand (not and the tolerance limits. shown) for applying to the differential amplifier 3 in According to the present invention, there is provided analog form the actual or measurement value obtained a method of evaluating a measurement value of a testin respect of the part under test. A difference is formed ing stand, comprising setting a measurement value in in the differential amplifier 3 between the analog voltdirect relation to upper and lower tolerance values, age at the output of the converter 1, and the analog acpre-st0red in a storage means, comparing the measuretual or measurement value from the measurement cirmerit value to the upper and lower tolerance values and cuit. evaluating the part tested in dependence on this com- 40 The output signal of the differential amplifier 4 is apparison, and displaying the result of the comparison. plied to the Y-input of a dividing means 5. Therefore, The invention also provided apparatus for evaluating the following signals can appear at the Y-input of the a measurement value in a testing stand, comprising a dividing means 5:

+ lower limit value upper limit value:

Y-input is O upper limit value. lower limit value upper limit value:

Y-input is O lower limit value.

storage means for storing upper and lower tolerance The output signal of the amplifier 3 is applied to the values in respect to a part to be tested, digital-analog 5 X-input of the dividing means 5. Therefore the followconverter means for converting the stored tolerance ing signals can appear at the X-input of the dividing values into analog values, first difference-forming means 5:

+ lower limit value actual value:

X-input is O actual value lower limit value actual value:

X-input is O lower limit value.

means for forming a difference between the voltages The dividing means 5 carries out the operation X/Y corresponding to the lower and the upper tolerance so that the following signals can appear at its output:

+ actual value lower limit value upper limit value:

U, is O -Urnax lower limit value actual value upper limit value:

v U, is 0 l lower limit value upper limit value actual value:

U, is +1 Umax.

values, second difference-forming means for forming a Connected downstream of the dividing means 5 IS a difference between the voltages corresponding to the display means in the form of an analog display 8, for demeasurement value and the lower tolerance value, the livering an indication of the test value tendency. By

forming the difference between the voltages corresponding to the upper and the lower tolerance values, the sensitivity of the analog display can be controlled. A clear display can be achieved for the analog display by virture of the fact that the nought level coincides with the marking for the lower tolerance value and the one level coincides with the marking for the upper limit value. The area between the nought level and the one level can be filled in with a green color. A linear scale division of 100 0 percent is provided between the nought level and the one level on the scale marking. A pointer (not shown) of the analog display 8 gives a percentage value which corresponds to the actual value of the measurement established on the testing stand. This establishes a direct and easily read relation between the actual value of the measurement, and the ideal value which lies at 100 percent on the scale marking, and also the two tolerance values which lie at 0 percent at the respective ends of the scale. With this ar rangement for example, the left-hand 0 percent value can correspond to the lower tolerance value and the right-hand 0 percent value can correspond to the upper tolerance value.

The apparatus can also have two display lamps 9 and 10 for also giving an additional optical display to indicate whether the actual value goes beyond the lower or upper tolerance values respectively. The scale of the analog display 8 can have red areas on respective sides of the two 0 percent markings to indicate that the actual value is outside the range between the upper and lower tolerance values. For cutting in the display lamps 9 and 10 there are two Schmitt triggers 6 and 7 which switch at the nought level and the one level respectively of the analog display 8.

The above-described method and apparatus provide the advantage that, besides qualitative evaluation by a good-bad indication, a quantitative indication can be made as to the extent to which the actual or measurement value has deviated from the ideal value, which makes it possible to make a prediction as to the functional efficiency still present in the part being tested. In

- particular an indication can be made as to the extent to which functional efficiency of the part deviates from the ideal value or approaches the limit values, for example due to wear.

With a series of motor vehicle parts to be tested, this information makes it possible to arrive at conclusions concerning the probable future working life or operational life without subjective data comparison and complicated calculations. In the case of adjustment work, the display, at the analog display 8, of the tendency of the test measurement value, can be of advantage as, during adjustment operations, the work personnel only has to carry out adjustments on the tested part, in such a way that the pointer displaying the tendency of the test value on the analog display 8 comes to lie at the percent marking, which corresponds to the ideal value. Repair work can be substantially facilitated thereby, since the personnel do not have to read complex data sheets or measurement values.

Many changes and modifications in the abovedescribed embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, that scope is intended to be limited only by the scope of the appended claims.

What is claimed is:

1. Apparatus for evaluating a measurement value in a testing stand, comprising storage means for storing upper and lower tolerance values in respect to a part to be tested, digitalanalog converter means for converting the stored tolerance values into analog signals,

first difference-forming means for forming a difference between the signals corresponding to the lower and the upper tolerance values,

second difference-forming means for forming a difference between the signals corresponding to the measurement value and one of the tolerance values,

the first and second difference-forming means being connected to receive the output signals of the digital-analog converter means, dividing means connected to the outputs of the first and second difference-forming means, and

display means connected to the dividing means for displaying the result of the comparison between the measurement value and the upper and lower tolerance values.

2. Apparatus according to claim 1 wherein the display means is an analog display, the arrangement being such that the analog nought value is brought into coincidence with the lower tolerance value and the analog one value is brought into coincidence with the upper tolerance value.

3. Apparatus according to claim 2 wherein the analog display has a scale division of 0% 100% 0% between the analog nought value and the analog one value.

4. Apparatus according to claim 1 also including two display lamps operable to indicate if the measurement value goes outside the range of values between the lower and the upper tolerance values.

5. Apparatus according to claim It in which said second means forms a difference between the lower tolerance value and the measurement value. 

1. Apparatus for evaluating a measurement value in a testing stand, comprising storage means for storing upper and lower tolerance values in respect to a part to be tested, digital-analog converter means for converting the stored tolerance values into analog signals, first difference-forming means for forming a difference between the signals corresponding to the lower and the upper tolerance values, second difference-forming means for forming a difference between the signals corresponding to the measurement value and one of the tolerance values, the first and second difference-forming means being connected to receive the output signals of the digital-analog converter means, dividing means connected to the outputs of the first and second difference-forming means, and display means connected to the dividing means for displaying the result of the comparison between the measurement value and the upper and lower tolerance values.
 2. Apparatus according to claim 1 wherein the display means is an analog display, the arrangement being such that the analog nought value is brought into coincidence with the lower tolerance value and the analog one value is brought into coincidence with the upper tolerance value.
 3. Apparatus according to Claim 2 wherein the analog display has a scale division of 0% . . . 100% . . . 0% between the analog nought value and the analog one value.
 4. Apparatus according to claim 1 also including two display lamps operable to indicate if the measurement value goes outside the range of values between the lower and the upper tolerance values.
 5. Apparatus according to claim 1 in which said second means forms a difference between the lower tolerance value and the measurement value. 